* Chipmakers investing to meet booming demand
* News comes on heels of Vice Chairman Lee's release from jail (Adds analyst comment)
SEOUL, Feb 7 (Reuters) - Samsung Electronics Co Ltd has decided to begin investment to build a second memory chip line at its Pyeongtaek production facilities in South Korea, Yonhap news agency reported on Wednesday.
Chipmakers are investing heavily to meet booming demand for semiconductors and Samsung said last year it plans to invest 14.4 trillion won in its new NAND chip factory in Pyeongtaek by 2021.
Samsung declined to comment on the Yonhap report.
Samsung's first semiconductor production line at Pyeongtaek began mass production in July last year.
"After this year's scheduled investment into the first Pyeongtaek line is over, it will be operating at more than 70 percent capacity," Lee Jong-wook, an analyst at Samsung Securities, wrote in a note on Wednesday.
In late January, Samsung posted a record annual profit driven by a so-called memory chip "super-cycle," and said it expects demand for semiconductors to remain strong in 2018, especially for chips used in servers.
The announcement follows Samsung Electronics Vice Chairman Jay Y. Lee leaving a South Korean jail a free man on Monday after a panel of judges suspended his sentence for charges that included bribery and embezzlement. (Reporting by Joyce Lee and Ju-Min Park; Editing by Richard Pullin and Edwina Gibbs)